Aim. To compare the results of a single tract versus multi-tract percutaneous nephrolithotomy (PNL)
Materials and methods. Over a period of 6 years, a total of 2,264 PNLs was performed at the N.A. Lopatkin Scientific Research Institute of Urology and Interventional Radiology, of which 875 PNLs were done for stage K3-K4 staghorn calculi. Among them, 244 (27.7%) patients underwent multi-tract PNL. We included 873 patients in our study. The median stone size was 59 (46; 88) mm. Two, three and four percutaneous tracts were used in 165 (67.6%), 63 (25.8%) and 14 (5.7%) patients, respectively. In 126 of 244 (52%) patients, a set for mini-percutaneous surgery with 14.5 and 15.5 Ch tubes was used as additional access.
Results. The effectiveness of single and multi-track PNL was 53.6%, and 83.8%, respectively. The mean operating time for PNL using one, two, three and four percutaneous tracts was 77.2±29.9, 85.7±26.9, 116.6±28, and 144.0±12.2 min, respectively. The median length of hospital stay for single and multi-track PNL was 6.6 (5.4, 8.7) vs. 10.2 (8.6, 12.3) days. Intra- and early postoperative infectious complications occurred in 101 (16.1%) and 54 (22.4%) patients, who underwent single and multi-track PNL, respectively. Bleeding occurred in 88 (13.9%) and 50 (20.8%) patients, respectively. After single and multi-track PNL, 54 (8.6%) and 21 (8.8%) patients needed a blood transfusion, respectively.
Conclusion. Multi-track PNL is highly effective as a treatment modality for patients with complex forms of nephrolithiasis. Using the mini-tool significantly reduces the risk of bleeding when performing the additional access.

Keywords: multi-track percutaneous nephrolithotomy, PNL, percutaneous nephrolithotomy, staghorn nephrolithiasis, urolithiasis